Patents by Inventor Gerhard Fennhoff

Gerhard Fennhoff has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5399600
    Abstract: The present invention provides blends of polycarbonates and triphenylphosphane sulphonates and optionally fluorinated polyolefins and/or further customary additives, together with a process for the production of the blends according to the invention.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: March 21, 1995
    Assignee: Bayer AG
    Inventors: Hans-Josef Buysch, Gerd Fengler, Gerhard Fennhoff, Klaus Horn
  • Patent number: 5393835
    Abstract: 1. Thermoplastic molding compounds containingA. 5 to 95 parts by weight of an aromatic polycarbonate,B. 1 to 50 parts by weight of a vinyl copolymer andC. 5 to 95 parts by weight of one or more graft polymers obtained by graft polymerization,characterized in that 10 to 100% of component A is replaced by a mixture of two polycarbonates A.1 and A.2 of identical structure,1) the relative solution viscosity of A.1 being 1.18 to 1.24,2) the relative solution viscosity of A.2 being 1.24 to 1.34 and3) the difference between the relative solution viscosities of A.1 and A.2 being greater than or equal to 0.
    Type: Grant
    Filed: May 18, 1993
    Date of Patent: February 28, 1995
    Assignee: Bayer Aktiengesellschaft
    Inventors: Thomas Eckel, Dieter Wittmann, Gerhard Fennhoff, Jochen Schoeps, Karl-Heinz Ott, Wolfgang Jakob
  • Patent number: 5382605
    Abstract: A thermoplastic molding composition resistant to the degradation induced by ionizing-radiation is disclosed. The composition contains an aromatic polycondensate and an agent which is a compound conforming structurally to formula (I) ##STR1## or which is a member selected from the group consisting of oligocarbonate, polycarbonate, copolycarbonate, polyestercarbonate and polyesters which contain structural units conforming to formula (Ia) ##STR2## wherein R.sup.1 to R.sup.10 and X are defined. The composition is suitable for the manufacture of shaped articles, especially articles useful in medical applications.
    Type: Grant
    Filed: February 15, 1994
    Date of Patent: January 17, 1995
    Assignees: Miles Inc., Bayer Aktiengesellschaft
    Inventors: Douglas G. Powell, Charles E. Lundy, Gerhard Fennhoff, Ralf Hufen, Klaus Kircher
  • Patent number: 5376715
    Abstract: The invention relates to silicon compounds, to mixtures thereof in aromatic polycarbonates and aromatic polyester carbonates and to their use as heat stabilizers in aromatic polycarbonates and aromatic polyester carbonates.
    Type: Grant
    Filed: January 18, 1994
    Date of Patent: December 27, 1994
    Assignees: Bayer Aktiengesellschaft, Miles Inc.
    Inventors: Gerhard Fennhoff, Jurgen Kirsch, Karsten-Josef Idel, Klaus Kircher, Charles Lundy
  • Patent number: 5357028
    Abstract: A catalytic method for preparing thermoplastic carbonate polymers is disclosed. In the method according to the interfacial polycondensation process or the homogeneous solution process, resins which containing catalytically active groups are used as catalysts. The resulting resins are characterized by their color stability and temperature stability.
    Type: Grant
    Filed: September 28, 1993
    Date of Patent: October 18, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Ralf Pakull, Gerhard Fennhoff, Werner Struver, Jurgen Kirsch
  • Patent number: 5302774
    Abstract: The invention relates to a process for the production of bisphenols from acetone and phenols in the presence of sulfonic acid ion exchanger resins modified with alkyl-SH groups, in which 0.6 to 5% by weight H.sub.2 O is added to the mixture of phenol and acetone before the reaction.
    Type: Grant
    Filed: August 9, 1993
    Date of Patent: April 12, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Klaus Berg, Hans-Josef Buysch, Alfred Eitel, Gerhard Fennhoff, Otto Immel, Ralf Pakull, Bernhard Wehrle, Claus Wulff
  • Patent number: 5288923
    Abstract: A process for the preparation of hydroxyalkyl ethers of diphenols is disclosed. Accordingly, aromatic polycarbonate resin is reacted with alkylene diol in the presence of a basic catalyst, at temperatures of 150.degree. to 250.degree. C. at a molar ratio of 514 10 moles of alkylene diol to 1 mole of aromatic carbonate structural units to produce the corresponding hydroxyalkyl ether. Additional embodiments entail optional reactions of the aromatic polycarbonate with cyclic alkylene carbonate and with open chain monomeric bis-(hydroxyalkyl)-carbonate. Aromatic polycarbonate waste may thus be advantageously recycled.
    Type: Grant
    Filed: January 29, 1993
    Date of Patent: February 22, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Fennhoff, Wolfgang Jacob, Manfred Ehlert
  • Patent number: 5214072
    Abstract: A process for the purification of waste of thermoplastic resins containing at least one member selected from among aromatic polycarbonates, aromatic polyester carbonates and aromatic polyesters and at least one of aluminum, lacquers and dyes which waste accumulates in the production of optical moldings is disclosed. The process which entails size reduction of the waste, chemical wash and filtering steps yields purified resins suitable for thermoplastic processing.
    Type: Grant
    Filed: October 8, 1992
    Date of Patent: May 25, 1993
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Fennhoff, Wolfgang Jakob, Manfred Ehlert
  • Patent number: 5162411
    Abstract: A carbonate corresponding to formula (I) ##STR1## in which R is aromatically bound polystyrene moiety and --O--D--O-- is a diphenolate moiety in which --D-- is a divalent group containing 6 to 30 carbon atoms and r is 0 or 1 is disclosed. The carbonate is useful as a flow aid for thermoplastic molding compositions.
    Type: Grant
    Filed: July 11, 1991
    Date of Patent: November 10, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Fennhoff, Uwe Westeppe, Werner Nouvertne, Karsten-Josef Idel, Edgar Leitz, Ulrich Grigo
  • Patent number: 5155205
    Abstract: New aromatic polycarbonates contain, in their bisphenol moiety, at least in part bisphenols of the type 1,1-bishydroxyphenylhexafluorodichlorocyclopentane, 1,1-bishydroxyphenylheptafluoromonochlorocyclopentane or 1,1-bishydroxyphenyloctafluorocyclopentane.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: October 13, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wolfgang Ebert, Michael Negele, Gerhard Fennhoff
  • Patent number: 5151452
    Abstract: A process is disclosed for the purification of lacquer-and optionally dye and metal- containing waste of thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates. The waste which result upon the production of moldings, such as audio compact discs, lenses for spectacles or head-lamp reflectors is processed in accordance with the invention to yield useful resin suitable for reprocessing as a molding resin. In accordance with the process, the waste is first size-reduced and then heated with acid to the reflux temperature while stirring. After a water wash there is followed a drying step. In accordance with the process, in instances where the waste does not originally contain metal, the metal in powder form is added before the acid treatment.
    Type: Grant
    Filed: September 17, 1991
    Date of Patent: September 29, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Fennhoff, Wolfgang Jakob, Manfred Ehlert, Dieter Freitag